Control device and solar power generation system

A solar power generation system, comprising:

• a plurality of solar cell module groups connected in series with each other, each of the plurality of solar cell module groups including, respectively, a plurality of solar cell modules;
• an inverter connected to the plurality of solar cell module groups, the inverter configured to convert DC power generated by the plurality of solar cell modules included in the solar cell module groups into AC power;
• and
• control devices respectively installed in the plurality of solar cell module groups, each of the control devices configured to control a respective one of the plurality of solar cell module groups by MPPT control, the control devices each including
• an opening/closing unit comprising a semiconductor relay and a mechanical relay and being configured to open and close a connection between the respective one of the plurality of solar cell module groups and the inverter, and
• a control unit configured to control opening and closing of the opening/closing unit in response to a control signal from the inverter, wherein
• in a case of connecting a given one of the plurality of solar cell module groups and the inverter, the respective control unit turns ON the respective semiconductor relay to turn ON the respective mechanical relay, and then turns OFF the respective semiconductor relay while the respective mechanical relay is in an ON state, and in a case of cutting off the connection between the plurality of solar cell module groups and the inverter, the control unit turns ON the respective semiconductor relay to turn OFF the respective mechanical relay, and then turns OFF the respective semiconductor relay while the respective mechanical relay is in an OFF state.